Lower body negative pressure recapitulates upright posture during supine exercise cardiac magnetic resonance imaging

Motivation: Supine positioning causes a hemodynamic shift towards the central circulation, minimizing changes in cardiac function during exercise cardiac MRI (cMRI). Goal(s): Simulate upright posture during supine exercise cMRI. Approach: Lower body negative pressure (LBNP) pants were constructed in-house and used to simulate upright posture during supine exercise cMRI. Results: Simulating upright posture during exercise cMRI with LBNP doubles the dynamic range of stroke volume, recapitulating the cardiac hemodynamic response expected during exercise in the upright posture. Impact: The results herein highlight the importance of performing exercise cMRI under conditions that simulate normal upright posture, and move exercise cMRI one step closer to broad clinical adoption.